The invention relates to non-linear editing systems and the storage and retrieval of the media associated with the system, i.e., video and audio data.
Non-linear editing on computer oriented systems involves digitizing media data recorded from a linear source, e.g., a video tape cassette, and storing the digitized media data on a storage device, e.g., a hard disk drive. Once digitized, the media data can be accessed quickly at any point in the linear sequence in which it was recorded so that various portions of the data can be accessed and edited in a non-linear way.
Editing in either a linear or non-linear system involves a similar principle. Source material from some source (video tape, audio recording, film etc.) is broken down into a series of separate "clips" representing the material desired for the final master, and then reassembling these "clips" into a final sequence achieving the desire of the editor and producer. "Clips" can be either video or audio materials or both (synchronous audio and video). In a non-linear system the typical approach involved allotting to each clip an associated digitized section of the original source in storage on the system in a "media file." The system would allow the user to manipulate the clips in order to produce the final sequence. The clips referred to the media files when certain specific information about the source media was needed, such as the original source name or nature of the media (video or audio), or when the need arose to actually view or hear (i.e., play) the media associated with the clip.
For example, a user editing on a non-linear system had the ability to manipulate clips into any order, use audio clips with other video clips, and create new clips by using smaller pieces of other clips. Tools existed to allow the user to combine clips of similar material for other effects. Video clips were used in combination to create dissolve effects, and audio clips to create various audio effects.
Typically, the output of an edit, i.e., an editing procedure such as the one described above, is an "Edit Decision List" (EDL) which can be used either by a conventional on-line editing system such as the CMX300 or a non-linear system to create or assemble a new linear sequence from other existing linear source material, e.g., video tape. The EDL is used to direct the on-line system to locate or "cue" the first frame of a desired clip which is recorded on a source video tape and loaded into a video tape recorder (VTR). The editing system then records the cued clip onto a target or destination medium, e.g., video tape, and cues the first frame of the next desired clip. (Note that the next desired clip may be recorded on the same or a different physical source medium as the first clip). Once cued, the editing system records the next desired clip onto the target medium. This process is repeated until the EDL is exhausted and the target medium represents the selected original material reorganized into the sequence described by the EDL.
The standard or conventional method when establishing a system of media archival is as follows: As each clip of source material is captured for storage in the system, the information about the clip and its actual digitized data is either coresident or linked directly at the time of the capture. Whenever the clip is referenced by the user of the system, the media associated with it is always the same particular one that was associated with it at the time of the capture (whether the media was digitized or actually was still intact on the original source). Any manipulation or editing concerning the clip or segment would directly use the media data tied to it for viewing or playback. Any information about the source that it came from or equivalent sources would need to be stored with each clip or segment. As such, the whole collection of clips or segments would be needed at any time in order to determine the breadth of any source relationships. And as new source relationships were developed it would be difficult if not impossible to inform all clips or segments of the new information. Additionally, tying the media data directly to a clip or segment would make it necessary to duplicate media data if certain clips or segments overlapped or were contained entirely within one another.
The invention solves these and other difficulties and problems.